Brake gear for vehicles



H. R. MASON.

BRAKE GEAR FOR VEHICLES.

APPLICATION FILED DEC.28. I9II.

Patented Apr; 25, 1922.

4 SHEETS-SHEET I.

Z] @60 2 2 p w, .y aw

H. R. MASON.

BRAKE GEAR FOR VEHICLES.

APPLICATION FILED nmzs. 1912.

'1 ,41 3 ,865, Patented Apr. 25, 1922.

4 SHEETSSHEET 2.

H. R. MASON.

BRAKE GEAR FOR VEHICLES.

APPLICATION FILED 015028.191].

Patented Apr. 25 1922.

4 SHEETSTSHEET 3.

r p Y. N

MM v m %WN I H. R. MASON.

BRAKE GEAR FOR VEHICLES.

APPLlCATlON FILED DEc.2a,1917.

Patentd Apr. 25, 1922. v

4 $HEETSSHEET 4.

names: stares mattresses.

HARRY :a. Mason, or ciicrieo, ILLINOIS.

I BRAKE GEAR ron vnnrcrins.

Specification of Letters Patent. Patgnted Apr, 25, 1922,

Application filed December 28, 1917. Serial No. 309,201.

Brake-gear as commonly provided when operated to brake the wheels of a vehicle, presents the serious disadvantage, under certain conditions of use, of grippingthe wheels with such firmness, that the wheels cease to rotate while the vehicle continues its movement, the wheels thus sliding on the. rails and producing what is commonly termed flat-wheels.

VVhile the arresting of the rotation of the wheels may occur as to all of the wheels of a vehicle, which are operatedas a unit from a single air-pressure operated mechanism, this arresting of the rotation of the wheels commonly occurs as to certain only of the wheels where the relations of the wheels and the brake-gear are such, or such other conditions exist, that the grip of the shoes on the wheels exceeds that of the other.

substantially all of the retarding force of the set of wheels on the one brake hanger for the moment. I

Various means for preventing flatwheels have been devised, but so far as it is known to me such means have involved the reduction of the air-pressure supplied to the brake mechanism which presents many disadvantages of which the chiefone is that in the event of the reduction of the air-pressure of theentire'system on avehicle, by the operation of the portions of the brake mechanism co-operating with any set of wheels for reducing the pressure eX-' erted by the brakes on such set of wheels, the braking force exerted by the brakes for all the other sets of wheels is simultaneously reduced, regardless of the pressure applied shown in F by such other brakes, thus causing all of I the brakes on the vehicle to be partially released and, therefore, impairing-the brakiunctlo ,5 I My primary objects,jgenerally stated, are

to provide novel," simple, and positively opcrating mechanism whichshall operate automatically to prevent flat-wheels regardless ofthe particular conditions ofthe. track, and which will operate for each wheel independently of the others thereof, to relieve the braking-pressure exerted bythose brakes only which grip the wheels sufiiciently to produce fiat-wheel's? if not relieved, and I thus ensure the obtaining oi themaximum braking-eifect; to provide for the maximum braking action of a brake and reduce its braking action only when the pressure applied by the brake, if it were to continue, I is suific1ent to cause the wheel to stop rotating while the vehicle is in motion; and to provide for the rapid return of the brake mechanism to its normalposition, upon the release of the brake, in order that it may be again operated under normal conditions.

Referring to the accompanying drawings:

Fig. l is a broken view in side elevation, of a truck of a car, showinga-portion of one or" the wheels thereof, to which my improved brake-gear is applied. Fig. 2 is a view in end elevation of the structure 1, the structure being viewed from the righthand side in this figure. Fig.

2-3. is a section taken at the line 3 on Fig.I1-.

and

being shown partly. broken away.. Fig. 4: is a vie 111 sect1onal elevation 01 a part of the yiewed in the direction of thearrow, the wheel with which the brakecooperates,

structure shown in Fig. 1, the section being V hrection or the arrows. Fig, 5 is a sec tion taken atthe irregular line 55 on Fig. 4 and viewed in the direction of the arrows. Fig. 6 is a plan viewof aportion of the structure shown in F ig. 1, certain parts bebroken away. Figs. 7 and 8. are plan n at the line ieton Fig. 5 and viewed in tion of the lever mechanism of the brakegear which directly co-operates with the clutch mechanism referred to, together with the guide for the same, the clutch mechanism being removed. Fig. 11 is aface view of the clutch operating member of Fig. 10 which operates in the guide member of said figure; and Fig. 12 a section taken at the line 12 on Fig. 5 and viewed in the direction of the arrow.

A portion of the truck of a car is repre sented at 13, this truck being equipped with wheels, one of which is represented at 14. In the particular construction shown, my

' invention is illustrated as applied to a car employing air-pressure operated brakebeams in accordance with common practice, one of these brake-beams being represented at 15 and in the operation of the air-pressure operated mechanism of the car, to apply the brakes, swinging toward the wheel to the left inFig. 1.

In accordance with the preferred embodiment ofmy invention, the brake-head represented at 16 and carrying the brake-shoe 17 for co-operation with the wheel 14, is hung from a pair of rods 18 spaced apart and connected with the head 16 through the medium of a pivot-pin 19, these rods extending upwardly and being pivoted, through the medium of a pin 20 with a reciprocable bar 21 guidingly confined in a channel 22 in a guide member 23 rigidly secured to a cross member 24 of the truck 13, this bar being provided on one face with upper and lower shoulders 25 and 26 spaced apart for cooperation with clutch mechanism hereinafter described, the member 23 having a depending portion23 presenting a lug 27 with the under surface of which a lever hereinafter described and connected with the brake-head, co-operates.

Extending at its lower end through a bifurcated portion 28 on the brake-beam 15 which is located inv a bifurcated portion 16" of the brake-head 16, is a lever 29 pivotally connected at its lower extremity with the pin 19 and pivotally connected above the pin 19, with the yoke-portion 28 through the medium of a pin 30. The lever 29 above these pivots is laterally offset, as represented at 31, to provide a surface 32 for co-operation with the underside of the lug 27 as hereinafter described, this lever at the upper extremity of its opposite portion containing an elongated slot 33 at which it straddles a pin 34 mountedin the depending, bifurcated, portion 35 of a head 36 providing spaced bearings 37 and 38 in which a shaft- 39, from which the member 36 is hung, is journaled at its ends. The shaft 39 is located in, and supported by, a clutch-device formed of upper and lower clutch-members 40 and 41, respectively, these members being curved as indicated at 42 and 43 respectively, at

the surfaces thereof which contact the shaft on the bar 21, these lugs co-operating with shoulder portions 49 and 50 on the member 23 for a purpose hereinafter explained. The member 41 at the other side of the shaft 39 contains a socket 51 housing a coiled spring 52-which co-operates with the head 53 of a plunger-'54 extending upwardly through the member 41 and through the member 40, the upper end of this plunger being threaded and carrying nuts 55 and 56, one of which is a lock-nut, the spring 52 operating to clamp the members 40 and 41, about the shaft 39 for a purpose hereinafter explained. The shaft 39 carries a ratchet-wheel 57 nonrotatably supported thereon as by the key 58, this ratchet-wheel co-operating with a dog 59 reciprocably mounted in a guide-way 60 in the member 36 and backed by a spring 61 which releasably holds the dog in engagement with the ratchet, these parts being so constructed and arranged as shown that the tooth of the dog 59 engages the shouldered portions of the teeth of the ratchet which prevents rotation of the member 36 in clockwise direction in Fig. 4, unless the pin 39 rotates with this member, but permits the member 36 to freely rotate on the shaft 39 in anti-clockwise direction in Fig. 4.

The normal position of the brake mechanism is that illustrated in the drawings. When the air-brake mechanism of the car is operated, the brake-beam 15 swings to the left in Figs. 1 and 4 and through the medium of its connection with the brake-head 16, by means of the lever 29 and pin 19, the brake-shoe is movedinto frictional engagement with the wheel 14. In the said movement of the parts, the lever 29 swings, and slides, upon the pin 34, the member 36 being. held against clockwise rotation in Fig. 4 by the clutching action of the members 40 and 41 under the pressure exerted bythe spring 52, and the rods 18 swing at the pivot 20 on the clutch-releasing bar 21, the surfaces 27 and 32 remaining out of contact during this movement of the parts. The brake-shoe 17 in gripping the wheel 14 is caused to exert upward or downward movement depending upon whether the wheel is rotating in anticlockwise direction or in clockwise direction in Fig. d and thus exerts an upward or downward thrust, as the case may be, upon the rods 18 and consequently upon the clutchreleasing member 21. So long as this upward or downward thrust on the bar 21 is not sufficient to overcome the resistance of v the lever 29 to abut the lug 27, thereby reducing the leverage exerted by'the brakebeam 15 against the brake-Thead and com mensurately relieving the pressure exerted by the shoe against the wheel, it being understood that when the bar 21 is pulled downwardly to release the clutch mechanism as stated, the member ll is prevented from turning by engagement of this lug 48 with the surface 50 and when the member 21 is pushed upwardly to release the clutch mechanism the member 40 is prevented from turning by engagement'of this lug 47 with the surface 49. 1

It will be noted from the foregoing that the particular illustrated embodiment of my invention operates upontheprinciple of automatically reducing the power exerted, by the brake-beam upon the brake-shoe when the force exerted by the shoe in an upward or downward direction, depending upon the direction inwhich the wheel is rotating,;exceeds a predetermined degree.

In the equipping of vehicles with my invention, it is desirable that one of the mechanisms described and illustrated be asso-' ciated with each brake-shoe and as the automatic relieving of the braking-pressure, as hereinbefore described, is accomplished with-- out reducing the applied air-pressure, the relieving of the pressure exerted by the brake-shoe of any wheel by the existence of such conditions as will cause the bar 21 to overcome the resistance of the spring 52 and release the clutch, will not affect the normal operation of the brakes co-operating with the other wheels, which is a great advan-,.

It will be readily understood that it is de-.

sirable that provision be made for securing as nearly as possible, the maximum braking effect, and in accordance with the preferred embodiment of my invention, I provide for v the obtainingof substantially the maximum brakingefiect, by so adjusting the spring 52 that the clutchdevice controlled thereby is released only, when the upward or downward, thrust exerted against. the clutch releasing bar 21 exceeds the degree. of thrust.

imposed upon this bar when. the brakes are exerting their maximum power. In this connection itmay be stated that between the time of initial, application of the brake and v with,"the brakeshoe is caused to be forcibly] jerked upwardly or downwardly, depending upon the direction of rotation of the'wheel,

the skidding of the wheelco-operating thereand it has been found by the making oftests that the force exerted upwardly or downwardly by the brake-shoe, when the jerking action above referred to occurs, is greatly increased over the force exerted upwardly or downwardly, as the case may be, by the brake-shoe under ordinary, conditions. This increase in. force, by reason of its degree thereof provides a very iwide margin be-.

tween maximum braking effect and abraking action which, if continued, would cause flat-wheels to be produced, solthatif the brake apparatus is set to become released when this jerking. action takes place, it will permit the apparatus to operate in practice under the varying conditions. which are presented! Ltherefore, prefer to so adjust the.

spring 52 to the various brake mechanisms that the resistance 'of the same will not be overcome until the jerking action of .the

brakeshoe, as above stated, has occurred.

By such as arrangement the maximum braking effect exertedby the brakes may be ob tained as to all of the brakes of avehicle I and inthe event that a condition, is brought about which would result. in any of the wheels ceasing to rotatewhile the vehicleis in motion and thus producing flat-wheels if allowed to skid along the track for a con slderable dlstance, the brak1ng pressure exerted by the brake for that particular wheel will'be reduced without affecting .the pressure exerted by the brakes for the other wheels.

It will also be understoodthat the chang- 7 ing of the fulcrum point of the lever 29fro1n its connection with thepin 34- to the abutment 27 to vary the power exerted by the brake-beam against the brake head, will dei pend upon the particular conditions presented by the vehicle to which the mechanism ,is applied, it being necessary, however, that the length of the effective portion of the lever 29 from the pivot 30 to the abutment 27, as compared with the leverage between V the pivots l9and 30, be such that under the maximum air-pressure applied in use to operate the brakes, the pressure exerted by the brake beam against the brake-head will be insufficient to cause the brake-shoe to grip th wheel with such pressure that the latter ceases to rotate while the car is in motion.

When the air-brakes of the car are re leased by the operator in accordance with common practice, at which time the shaft 39 is gripped by the clutch mechanism hereinbefore described, the member 36 is free to swing by gravity to normal position (Fig. 4) by reason of the ratchet and pawl arrangement provided as stated, and all of the parts of the mechanism return to the position shown in this figure.

The under surface of the lug 2'7 and the surface 32 of the lever 29 are so shaped and hear such relations to each other as shown, and the lever 29 so supported, viz. at the slotted portion 33, as to cause these surfaces to remain out of contact with each other in the normal operation of the brake mechanismregardless of the wear of the braking surface of the brake-shoe, but to become into abutting relationship immediately following the release of the clutch from the shaft 39 which permits the fulcrum 34 of the lever 29 to swing to the left in Fig. 4.

W hile Ihave illustrated and described a particular construction embodying my in vention, I do not wish to be understood as intending to limit it thereto, as the same may be variously modified and altered without departing from the spirit of my invention.

lVhat I claim as new and desire to secure by Letters Patent is- I l. The combination with a vehicle, of braking-mechanism for the wheels of the vehicle, and means associated with said braking mechanism-operating automatically to reduce the pressure of the brakes against any one of the wheels to prevent flattening of the wheel, without affecting the braking pressure against the others of the wheels.

2. The combination with a vehicle, of braking-mechanism for the wheels of the ve hicle, and means associated with said braking mechanism operating automatically to re duce the pressure of the brakes against any one of the wheels when the force exerted by the brakes in a direction tangentially of that wheel, exceeds a predetermined degree, without affecting the braking-pressure against the others of the wheels.

3. The combination with a vehicle, of braking devices for the respective wheels thereof, a single mechanism from whichsaid braking devices are operated, and a plurality of individually-operative means cooperating with the respective braking devices and op erating automatically to reduce the braking pressure applied to certain of said wheels to prevent flattening thereof, without effecting the braking. pressure exerted by the braking devices cooperating with the others of said wheels.

4. The combination with a vehicle, of sets Lei/3385' of braking devices for the respective sets of set or sets of wheels, without affecting the braking pressure exerted by the braking devices cooperating with the other sets of wheels.

5. The combination with a vehicle, of sets of braking devices for the respective wheels thereof, a single mechanism from which said braking devices are operated, and means operating automatically to reduce the power exerted by said mechanism against said braking devices, without reducing the power exerted against said first-named means from said source, to preventfiattening of the wheels.

6. The comblnation with a vehicle, of sets of braking devices for the respective wheels thereof, a single mechanism from which said braking devices are operated, and means op erating automatically to reduce the power exerted by said means against, said braking devices without reducing the power exerted against said first-named means from said source, when the force exerted by the braking devices in a direction tangentially of the wheels exceeds a predetermined degree.

7. The combination with a vehicle,'of a braking-device for a wheel of the vehicle, means for actuating said device to brake the wheel, and means operating automatically to reduce the power exerted by said means a 'ainst said braking-device to prevent flattening of the wheel, said last-named means including a shiftable member with which said first-named means andsaid brakingdevice are connected and through the medium of which said braking-device is operated, and fulcrums spaced. apart and co-operating with said shiftable member and between which and said braking device said firstnamed means are connected.

8. The combmation with a vehicle, of a braking-device fora wheel of the vehicle, 2

means for actuating said device to brake the wheel, and means operating automatically to reduce the power exerted by said means against sald braklng-device when the thrust exerted by the braking device in a direction I tangentially of the wheel exceeds a predetermined degree, said lastnamed means including a shiftable member with which said first-named means and said braking-device are connected and through the medium of which said braking-device is operated, and fulcrums spaced apart and co-operating with said shiftable member. andbetwe'en which and said braking-device said first-named means are connected.

'9. The combination with a vehicle, of a braking-device for a wheel of the vehicle, a shiftable device, means operating through the medium of said shiftable device for acituatlngsaid braking-device, means normally restralnlng movement of sald shift able device, means, controlled by said braklng devlce for actuating said last-named means to perm1tsa1d'shiftable device to move, and means co-operating zwlth sald shiftable device for changing the leverage exterted agalnst. said braking-'clevlce by said first-named means upon said movement of predetermined degree, and means co-operating with said shiftable device for changing the leverageexeited against said brakingdevice by said first-named meansupon said movement of said shiftable device.

' 11. The'combination with a vehicle, ,of a

braking-device for a wheel of the vehicle,

ashiftable device, means operating through the medium of said shiftable' device to actuate said braking-device, clutch mechanism normally restrainingmovement of said Shlfiie able dev1ce,,means controlled by said braking device for releasing said clutch mecha-' nism to permit said shiftable' device to move, and means co-operatlng with said shlftable device for 'changing'the leverage [exerted against said braking-deviceby said firstnamed means upon said movement of said shiftable device.

12. The Icombination with a vehicle, of a "braking-device for a wheel of the vehicle, a

the medium of said shiftable device to actuate said braking-device, clutch mechanism normally restraining movement or said shittwhen the force exerted by the braking device in a direction tangentially of the wheel, ex-

ceeds a predetermined degree, and means cooperating with ,said shiftable device" for changing the leverage exerted against said braking-device by said first-named means upon'said movement of said shiftable device. 7

13. The combination with avehicle, of a able member.-

braking-device for a wheel of the vehicle, a shlftable member, a lever :tulcrumed on-said 'member and operatively engaging said braking-device, means for actuating said brakingdevice engaging said' lever between the points at whlch the latter engages said member and operatively engages said braking-device,

said braking-device for actuating'said lastnamed means to permlt said shiftable member to move, anda member positioned to en means normally restraining movement of said shiftable member, means controlled by,

gage'said leverbetween the point at which it is fulcrumed on said shiftable member and the point at which power is applied to said lever by said first-named means, upon the shifting of said shiftable member.

14. The combinationwith a vehicle, of a braking-device for a wheel of the vehicle,'a shiftable' member, a lever fulcrumed on said member and operatively engaging said braking-device, means for actuating said braking-device engaging said lever between the points at which'the' latter engages said member and operatively engagessaid'brak- V ing-device, 7 means controlled by said; braking 'device for actuating said last-namedjmeans to permitsa-id, shiftable member: to" f move when the force exerted by the'braking-device in a. direction tangentially of the wheel exceeds ap'redetermined degree, and a member" positioned to I normally restraining -movement of said shiftable member, means engage said lever between thepoint at which it is fulcrumed on said shiftable member and the point at which power is'applied'to said lever by said first-named means upon'the v shifting ofsaid shiftable member;

15. The COmbHIEitlOII' .wlth a vehicle, of a ing-deviceengaging said'le'ver between the;

points at which the latterengages said me'mber and operatlvely engages sald bralr ngdevice, clutch mechanism for normally re straining ,movement of said shiftable memp xber, meanscontrolled by said braking-dc shlftable device, means operating through vice for actuating said clutch mechanism to permit said shiftable member to move, and a member positioned to'engage said lever be tween the'point at' which it is fulcrumed on said shiftablemember and the point at which power is applied to said lever by said first named means,'upon the shifting of said shift- 16. Thefcombination with vehicle, or braking-device for a'wheel of the vehicle," a

member operatively engaging said brakingdevice, means for actuating said brakingshiftable member, a lever fulcrumedbn said I w device engaging said lever betweenthe points at which the latter engages said member Cir and operatively engages saidbraking-device, clutch mechamsm for normally restraining movement of said shiftable member, means,

controlled by said braking-device for actuating said clutch mechanism to permit said shiftable member to move when the force exerted by the braking-device in a direction tangentially of the wheels, exceeds a predetermined degree, and a member positioned to engage said lever between the point at which it is tulcrumed on said shittable member and the point at which power is applied to said lever by said first-named means, upon the shifting of said shiftable member.

17. The combination with a vehicle, of braking-mechanism for the wheels of the vehicle and means associated with said braking mechanism operating automatically to reduce the pressure of the brakes against any of the wheels in the rotation of thelatter in either direction to prevent flattening of the wheels, without affecting the braking pressure against the others of the wheels.

18. The combination with a vehicle, of braking-mechanism for the wheels of the vehicle and means associated with said braking mechanism operating automatically to reduce the pressure of the brakes against any one of the wheels in their rotation in either direction, when the force exertedby the b airing-mechanism in a direction tangentially ofth at wheel, exceeds a predetermined degree, without affecting the brakingpressure against the others of the wheels.

19. The combination with a vehicle, or" braking devices for the wheels thereof, a single mechanism from whichsaid braking devices are operated, and a plurality of individually-operative means cooperating with the respective braking devices and operating automatically to reduce the braking pres sure applied to certain of said wheels, without aliecting the braking pressure exerted by the braking devices cooperating with the others of said wheels in the-rotation or" the wheels in either direction.

20. The combinationwith a vehicle, of braking devices for the respective wheels thereof, a singlemechanism from which said vbraking devices are operated, and a plurality of independently:operative means cooperating with the respective braking devices and operating automatically in the rotation 7 21. The combination with a vehicle, of a braking-device for a wheel of the vehicle, means for actuating saiddevice to brake the named means including ashiftable member with which said first-named meansand said braking-device are connected and through the medium of which said braking-device is operated, and fulcrums spaced apart and c0- operating with said shiitable member and,

between which and said braking-device said first-named means are connected. v

22. The combination with a vehicle, of a brakin -device for a wheel of the vehicle, means Ior actuating. said device to brake the wheel, and means operating automatically, in the rotation of the wheelqin either direction, to reduce the power exerted by said means against said braking-device when the force exerted by the braking-device in a di rection tangentially of the wheel, exceeds a predetermined degree, said last-named means including a shiftable member with which said first-named means and said'brakingdevice are connected and through the medium of which said braking-device'is operated, and fulcrums spaced apart and co-operating with said shittable member and'between which and said bralring device'said first-named means are connected.

23. The combinationwith a vehicle, of a brakingdevice for a wheel of the vehicle, a shiftable device, means operating through the medium of said shiftable device to actuate said braking-device, means normally restraining movement of said slii'ftable de vice, means controlled by said braking-device and "operating in the 'rotationof the wheel in either direction to'actuate said last- 2d. The combination with a vehicle, ofa

braking-device for a wheel oi the vehicle, a shiftable device, means operating through the medium of said .shiftable device to actuate said braking-device, clutch mechanism normally restraining movement of said shiftable device, mechanism controlled by said brakingdevice in the rotation of the wheel in either direction for actuatingsaid clutch-mechanism to permit said shiftable device to move,and means co-operating with said shi-itable device for changing the leverage exerted against said braking-device by said first-named means upon said movement of said shiftable device.

25. The combination with a vehicle, ofa braking-device for a wheel of the vehicle, a shiftable device, means operating through the medium of said shiftable device to actuate said braking-device, clutch mechanism 'normally restraining movement of said shiftable device, a shiftable member operating in its movement in either direction to release said clutch means to permit said shiftable device to move, said shiftable" member being operatively connected with braking-device engagin said lever between the points at which the latter engages said member and operatively engages said braking-device, means normally restraining movement of said shiftable member, means a controlled by said braking-device for actuating said last-named means to permit'said shiftable member to move, and a member positioned to engage said lever between the point at which it is fulcrumedonsaid shift able member and the point at which power. isa'pplied to said lever by said first-named meanspuponthe shifting of said shiftable member.

27. The combination with a vehicle of a braking-device for a wheel of the vehicle, a shiftable member carrying a fulcrum-pin, a lever containing an elongated slot through which said pin extends, said lever operatively connecting said brakingdevice, means for actuating said braking-device engaging said lever between the points at which the latter engages said member and operatively engages, said braking-device,

means normally restraining movement of said shiftable member, means controlled by said brakingdcvice for actuating said lastnamed means to permit said shiftable memher to move, and a member pos tioned to engage said lever between the point at which it is fulcrumed on'said shiftab'le member and the point at which power is applied to said lever by said first-named means, upon the shifting of said shittable member.

28. The combination with a vehicle, of

. braking-devices co-operating with the wheels of the V6l1lCl6,-I113&I1S for applying pressure to said braking devices, and automatically operating meansadapted to reduce the braking power on any individual wheel when the brakes of that wheel lock such wheel against rotation.

29. The'combination with a vehicle, of

braking-devices co-operating with the wheels of the vehicle, means for'applying pressure to said braking devices and including bra-kebeams, and automatically operating means adapted to transfer a portion of thepower delivered to any'oit' the braking devices, directly to the vehicle when such braking device locksthe wheel with which it co-operates against rotation. r

30. The combination'with a vehicle, of

braking-devices co-operating with the wheels of the vehicle, means'for applying pressure to said braking devices for setting the brakes, and means operating automtaically to reduce the braking power on any wheel of the vehicle, independently of the other wheels, while the brakes are set. 'i

31. The combination with a vehicle, oi: braking-mechanism for a wheel of the vehicle, mechanism operated by momentarilyacting increased pressure tangentially of the wheel at the instant rotation of the wheel is arrested and means controlled b said second-nanied mechanism, when operated as stated, to maintain braking pressure, but to a degree less than that necessary to exist to actuate said second named' mechanism. v

32.:The combination with a vehicle, of

brake-devices for the wheels of the vehicle,

means for operating said devices from a common source, and a plurality of individually operative meansco-operating with said brakingdevices and operating automatically to reduce the braking pressure on suc wheels without affecting the braking pres sure against the others of the wheels.

33. The combination with a vehicle, of

brakedevices for the wheels ofthe vehicle,

a single mechanism from which said braking devices-are operated, and a plurality of individually operating means co-operating with said brake-devices and operating automatically to reduce the braking pressure on such wheels and preventflattenin'g thereof, without affecting the braking pressure against the others of the wheels.

The, combination with a vehicle, of brake-devices for the wheels of theivehicle, a power device, mechanism operated by said power device and operatingto actuate said brake-devices, and means associated with said mechanism and operating automatically to reduce the pressure of) the brake-devices against any of the wheels through said mechanism, when the conditions presented are such that, it continued, flatteningof the wheels would result, without affecting the braking-pressure applied bythe othersof i said devices against any of the others of the wheels. i

35. The combination with a vehicle, or

brake-devices for the wheels of the vehicle,

. a fluid pressure operated power device, I

mechanism operated by said power device and operating automatically to reduce the pressure of the brake-devices against any of the wheels through said mechanism, when the conditions presented are such that, it continued, flattening of the wheels would result without aiiecting the braking-pressure applied by the others of said devices against any of the others of the wheels.

36. The combination with a'vehicle, of bralring-mechanism fora wheel of the vehicle, and means associated with said braking mechanism operating automatically to re duce the pressure of the brake against the wheel when the conditions presented are such that, it continued, flattening of the wheel would result, and maintain such pressure below the point at which skidding of the wheel may occurregardless of the degree of pressure between the brake shoe and wheel.

87. The combination with a vehicle, or" braking-mechanism tor a wheel of the vehicle, and means associated with said braking mechanism, and operating automatically to reduce the pressure of the brake against the wheel when the force. exerted by the brake in a direction tangentially ot the wheel exceeds a predetermined degree, and maintain such pressure below the point at which skidding ot the wheel may occur regardless oi the degree or pressure between the brake shoe and wheel,

38. The combination with a vehicle, of

brakingdevices for the respective wheels braking devices are operated, a source of compressed air for operating said mechanism, and a plurality of individually operative means cooperating with the respective braking devices and operating automatically to reduce the braking pressure applied. to

certain of such wheels, without affecting the brak ng pressure exerted by the braking devices cooperating with the others of said wheels.

40. The combination with a vehicle, of a ,b raking device for a wheel of the vehicle,

means for applying pressure to said braking device forsetting the brake, and means operating autom atically to reduce the power exerted by said firstnamed 'means. against said braking device and involving a spring device the resistance of which is required to be overcome before said second-named means operate and Wllii'll, when overcome,

ceases to act against said second-named means ll. The combination with a vehicle, of a braking device for a wheel of the vehicle, means for applying pressure to said braking device for setting the brake, and means operating automatically when the tangential force exerted by said braking device exceeds a predeter 'nineddegree, to reduce the power exerted by said first-named means against said braking device and involvinga spring device the resistance of which is required to be overcome. before said second-named means operate and which, when overcome, ceases to act against said second-named means. 1

The combination with vehicle, of" a braking device tor a wheel of the vehicle, lever mechanism. operatively connected with said braking device, means for actuating said lever mechanism, and automatically op erating means adapted to reduce the leverage exerted against said braking device through said lever mechanism for preventing flattening of the wheel, said lastnamed means involving a spring devicethe resistance of which is required to be overcome before said last-named means operate and which, when overcome ceases to act against said last-named means.

4L3. The combination with a vehicle, of a braking device for a wheel of the vehicle, levr mechanism operatively connected with said braking device, means for actuating said. lever mechanism, and automaticallyoperating means, operating, when the tangential force exerted by said braking device cxc eds a predetern'iined degree, to reduce the lev exerted'against said braking device through said lever mechanism for prevent ing flattening of the wheel, said last-named means involving a spring device the re.

sistance of which is required to be overcome before said last-named means operate and which, when overcome, ceases to act against said last-named means. I

a l. The combination'with a vehicle of a braking device for a wheel of the vehicle, and lever mechanism operatively connected with said braking device for reducingthe braking pressure at the braking device while the brake is set. and involving a releasable restraining device releasable when the tangential brake thrust exceeds a certain degree, said lever mechanism being constructed and arranged to cause, when operated, the tangentialbralre thrust to be. reduced below that required for the releasing of said releasing device.

45. The combination with a vehicle, of a braking device for a wheel of the vehicle,

' lever mechanism operatively connected with said braking device for redueingthe bralr 5 when operated they cannot be restored un til the brake is released.

46. The combination with a vehicle, oi a braking device for awheel of the vehicle,

lever mechanism operatively connected with said braking device for reducing the brak-o ing pressure at the brake device while the brakes are set, and operating automatically, when actuated, to reduce the braking pressure at the braking device and maintain it reduced until the brakes are released;

HARRY R. MASON. 

